integration question (1 Viewer)

[vds700]

find the integral of sin(x^0) dx

 

[Mark576]

int. sin(x⁰) dx = int. sin(1) dx = xsin(1) + C

 

[vds700]

int. sin(x⁰) dx = int. sin(1) dx = xsin(1) + C

thats what I got but the answer is (-180/pi) cos(x^0) + c

 

[RiSeAgAiNSt2538]

back of the book is not always right, they do make mistakes

 

[cwag]

no..the answers are right....it means sin xdegrees.

u can only integrate when the angle is in radians...therefore you it changes to

integral: sin (pi x/180)

= -180/pi cos (pi x/180)
= or -180/pi cos x(degrees)

 

[vds700]

its from a past half yearly ext 1 paper. I have scanned the sulution, I can't make sense of it (i have put an askerisk next to it). If anyone could explain it, that'd be great.

 

[cwag]

see above

 

[vds700]

no..the answers are right....it means sin xdegrees.

u can only integrate when the angle is in radians...therefore you it changes to

integral: sin (pi x/180)

= -180/pi cos (pi x/180)
= or -180/pi cos x(degrees)

where did you get the x from? Isn't it just the integral of sin(1 radian)?

 

[cwag]

where did you get the x from? Isn't it just the integral of sin(1 radian)?

no..x is in degrees....to change degrees to radians we multiply by pi/180

 

[vds700]

no..x is in degrees....to change degrees to radians we multiply by pi/180

ah ok so you're saying its the integral of sin( x degrees)? I swear in the question, it looks like x to the power of zero.

 

[cwag]

ah ok so you're saying its the integral of sin( x degrees)? I swear in the question, it looks like x to the power of zero.

hmm..yea they are very similar.....but i would assume that an angle rasied to the power of 0 is very uncommon in an integratio question

 

[DownInFlames]

OP: please clarify sin(x^0)

If you mean x degrees, you should never, ever write it like that [sin(x^0)] on the net because it means x to the power of 0. You can just use words.

 

[vds700]

OP: please clarify sin(x^0)

If you mean x degrees, you should never, ever write it like that [sin(x^0)] on the net because it means x to the power of 0. You can just use words.

it looks like a zero in the question but clearly its meant to be a degree sign

 

[mantiswhoprays]

well the integral of sinθ is -cosθ... so you could start there

 

[m&ss2008]

its very unlikely that theyll ask x^0

it does look very similar but if you look closely the degrees symbol will be rounder instead of an ellipse like zero

( o vs 0 )

 

[Mark576]

it looks like a zero in the question but clearly its meant to be a degree sign

Except he asked to find the integral of sin(x^0) lol. So my answer is correct. Granted though, if I knew this was a question directly from an exam, I would of assumed degrees. I assumed that perhaps he stumbled upon this in his working and forgot that x^0 = 1.

 

[mantiswhoprays]

i see what he's done... it is in degrees so he's turned x° into x rad. which would be π/180 x rad. go from there...

he had to change it to radians to be able to manipulate it to find the integral

 

[vds700]

Except he asked to find the integral of sin(x^0) lol. So my answer is correct. Granted though, if I knew this was a question directly from an exam, I would of assumed degrees. I assumed that perhaps he stumbled upon this in his working and forgot that x^0 = 1.

at first I thought it was sin(x^0) (its definitely a zero, not a circle like a degere sign, obviously they put the wrong symbol in). And I do know that x^0=1.

yeah i get it how you convert to radians then integrate.... thanks guys

 

[Slidey]

cwag is correct.